I tried a product last year that looked alot like the original Stacker 2's (my fav all time product). Yellow Bullets, 300 mg caffeine and 25 mg ephedrine alkaloids from Ma huang. I have tried the sida cordfolia and Lipodrene "ephedrine" products, nothing came close to the original. Yellow Bullet's were my last try at ephedra, and it rocks. The feeling is not the exact same, but so close it was awesome. The smell when I first opened the bottle was unmistakable, that was ma huang and the feeling was of the original ephedra.
Excessive caffeine or yohimbine or straight ephedrine hcl don't react well with me, this was most definitely a great ma huang stim.
Pretty expensive but for 100 caps, probably about $55 at most sites with shipping, it was well worth it.